Immunoglobulins and hypersensitivity Flashcards
What is the most common immunoglobulin?
IgG - 75%
What is the function of IgG?
Enhance phagocytosis of bacteria and viruses
Fixes complement and passes to foetal circulation
What is the shape of IgG?
Monomer
What is the 2nd most common immunglobulin?
IgA - 15%
Most commonly produced but lower serum concentration than IgG
What is the function of IgA?
Provides localised protection of mucous membranes
Where is IgA found?
Main Ig in breast milk
Sigestive, respiratory and urogenital tracts
What is the shape of IgM?
Pentamer
What is the function of IgM?
Fixes complement
What is the clinical significance of IgM?
First immunglobulin secreted in response to infection
Anti A and B antibodies
What is the function of IgD?
Activation of B cells
What is the function of IgE?
Mediates type 1 hypersensitivity reactions
Immunity to parasites
How is IgE synthesised?
Plasma cells
What does IgE bind to?
Fc receptors on mast cells and basophils
What is the least common immunoglobulin?
IgE
What are type 1 hypersensitivity reactions?
Anaphylactic
Atopic